1. Field
The present disclosure relates to a control device, a method, and an internal combustion engine.
2. Description of the Related Art
An excessive rise in the exhaust-gas temperature of an internal combustion engine provided with a supercharger results in an excessive rise in a turbine rotation speed and a supercharging pressure and increases the likelihood of a breakdown of the internal combustion engine. Therefore, as described in Japanese Unexamined Patent Application Publication No. 2012-229666, for example, a control technique of richening the air fuel ratio if there is a possibility of an excessive rise in an exhaust-gas temperature is known. Richening of the air fuel ratio brings about a decrease in the combustion temperature, which makes it possible to suppress a rise in the exhaust-gas temperature.